RAID 10 vs. RAID 6

Attribute	RAID 10	RAID 6
Minimum number of drives	4	4
Fault tolerance	High	Very high
Read performance	High	High
Write performance	Medium	Medium
Capacity utilization	50%	66.67%
Cost	High	Medium

Introduction

RAID (Redundant Array of Independent Disks) is a technology that combines multiple disk drives into a single unit to improve performance, redundancy, or a combination of both. RAID 10 and RAID 6 are two popular RAID configurations that offer different levels of performance and data protection. In this article, we will compare the attributes of RAID 10 and RAID 6 to help you understand the differences between them.

RAID 10 Overview

RAID 10, also known as RAID 1+0, is a combination of RAID 1 (mirroring) and RAID 0 (striping). In RAID 10, data is mirrored across multiple pairs of drives, and then those pairs are striped together for improved performance. This configuration offers both high performance and redundancy, as data can still be accessed even if one drive fails. RAID 10 requires a minimum of four drives to set up, and it provides excellent read and write performance.

RAID 6 Overview

RAID 6, on the other hand, is a configuration that uses block-level striping with two parity blocks distributed across all drives. This means that RAID 6 can withstand the failure of up to two drives without losing any data. RAID 6 requires a minimum of four drives to set up, and it offers a good balance between performance and data protection. However, RAID 6 is slower than RAID 10 in terms of both read and write performance due to the additional parity calculations.

Performance

When it comes to performance, RAID 10 is generally faster than RAID 6. This is because RAID 10 uses striping to improve read and write speeds, while RAID 6 has to calculate parity information for each write operation, which can slow down performance. RAID 10 is ideal for applications that require high performance, such as databases or virtualization environments, where speed is crucial. On the other hand, RAID 6 is better suited for applications that prioritize data protection over performance, such as archival storage or backup systems.

Data Protection

Both RAID 10 and RAID 6 offer data protection by allowing for the failure of one or more drives without losing any data. In RAID 10, data is mirrored across multiple drives, so if one drive fails, the data can still be accessed from the mirrored drive. RAID 6, on the other hand, uses dual parity blocks to protect against the failure of up to two drives. This means that RAID 6 can withstand more drive failures than RAID 10 before data loss occurs. However, the rebuild time for RAID 6 is longer due to the additional parity calculations.

Capacity

When it comes to capacity, RAID 6 offers more usable storage space compared to RAID 10. This is because RAID 6 uses two parity blocks, which allows for more efficient use of disk space. In RAID 10, half of the total drive capacity is used for mirroring, so the usable storage space is only half of the total capacity. RAID 6, on the other hand, uses only two drives for parity, so more drives can be used for data storage, resulting in higher usable capacity. If you need a large amount of storage space with data protection, RAID 6 may be the better choice.

Cost

When it comes to cost, RAID 10 is generally more expensive than RAID 6. This is because RAID 10 requires more drives to set up, as each drive needs to be mirrored with another drive. Additionally, RAID 10 offers better performance, which can also drive up the cost of the system. RAID 6, on the other hand, requires fewer drives and offers a good balance between performance and data protection, making it a more cost-effective option for many organizations. If budget is a concern, RAID 6 may be the better choice.

Conclusion

In conclusion, RAID 10 and RAID 6 are two popular RAID configurations that offer different levels of performance, data protection, capacity, and cost. RAID 10 is faster and better suited for applications that require high performance, while RAID 6 offers more storage space and better data protection. When choosing between RAID 10 and RAID 6, consider your specific needs and priorities, such as performance, data protection, capacity, and budget, to determine which RAID configuration is the best fit for your organization.